1. Technical Field
The present invention relates to semiconductor device packaging in general, and in particular to packaging for semiconductor devices having a column grid array. Still more particularly, the present invention relates to an apparatus for providing mechanical support to a column grid array package.
2. Description of the Related Art
Ceramic column grid array packages are commonly employed by many types of high-performance integrated circuit devices. Ceramic column grid array packages use solder columns to define electrical connections between a ceramic substrate (on which an integrated circuit chip is placed) and a printed circuit board. The solder columns are formed from high-melting temperature solder using an alloy of lead and tin. The aspect ratio of the solder columns used in a ceramic column grid array package is approximately 9:2, and the diameter of the solder columns is approximately 0.020 inches. The solder columns are first bonded to the ceramic substrate, and thereafter attached to the printed circuit board using conventional low-melting temperature solder paste reflow techniques that are well-known in the art.
One problem with ceramic column grid array packages is that the solder columns are susceptible to failures under high-frequency vibrations and shock tests. One approach to reinforcing the solder column connections of ceramic column grid array packages involves the placement of Kovar or Cusil pins in the corners of the ceramic column grid array packages to maintain the position of the ceramic column grid array package in relation to the printed circuit board in the presence of vibrations and compressive forces. Typically, Kovar or Cusil pins are first attached to a ceramic substrate by brazing, and the Kovar or Cusil pins are then positioned into holes located in a printed circuit board. However, the use of Kovar or Cusil pins results in numerous additional and complicate manufacturing steps. Thus, the above-mentioned usage of Kovar or Cusil pins are not commonly found in ceramic column grid array packages.
Consequently, it is desirable to provide an improved apparatus for providing mechanical support to ceramic column grid array packages.
In accordance with a preferred embodiment of the present invention, a ceramic column grid array package uses solder columns to provide electrical connections between a ceramic substrate and a printed circuit board. The ceramic substrate has two sides, with an integrated circuit chip mounted on one side and many input/output pads mounted on the other side. Solder columns are attached between the input/output pads and the printed circuit board. A corner post is located at each corner of the ceramic column grid array package to secure the position of the ceramic substrate in relation to the printed circuit board.
All objects, features, and advantages of the present invention will become apparent in the following detailed written description.